Arc protective mounting for tube socket or the like



Nov. 18, 1958 H. FREMONT 2,851,252

ARC PROTECTIVE MOUNTING FOR TUBE SOCKET OR THE LIKE Filed Feb. 14, 1955IN V EN TOR,

United States Patent ARC PRoTECTIvE MOUNTING FoR TUBE socKET 0R THE LIKEHerbert Fremont, Los Angeles, Calif., assigner to Calbest Engineering &Electronics Company, Los Angeles, Calif., a corporation of CaliforniaApplication February 14, 1955, Serial No. 488,069 2 Claims. (Cl.339-193) monly used is a pair of long polystyrene rods supporting thetube socket high above the chassis. This arrangement, although forthemost part. effective, consumes considerable space, and requiressubstantial clearance-above the chassis.

Yet even this arrangement fails in installations at high altitudes,especially, when moisture conditions are adverse.

Even in the ordinary installations, failure may occur due to the factthat a pip or point incidentally produced at the soldered connectionsinduces an arc discharge. Soldering must be skillfully and carefullydone at the socket posts to avoid this cause of failure.

It is another object of this invention to overcome these disadvantages,and provide a highly effective arc protective mounting for vacuum tubesand their sockets in which skillful soldering is not critical.

Itis another object of this invention to provide a highly compact arcprotective mounting for a vacuum tube and its socket, thereby savingappreciable space in the apparatus.

These objects are accomplished by providing a complete enclosure for thetube socket, the enclosure being made of a material having an extremelyhigh arcing potential.

It is another object of this invention to provide a device of thischaracter that is simple and inexpensive, and that can easily beassembled for use in the particular installation.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration of oneembodiment of the invention. For this purpose, there is shown a form inthe drawings accompanying and forming part of the present specification.This form will now be described in detail, illustrating the generalprinciples of the invention; but it is to be understood that thisdetailed description is not to be taken in a limiting sense, since thescope of this invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a side elevation of an insulation mounting incorporating thepresent invention, shown cooperating with an electronic emission tubeand in place upon a chassis;

Fig. 2 is an enlarged vertical sectional view, taken along the planecorresponding to line 2-2 of Fig. l, the tube being removed;

f. ICC

Fig. 3 is a sectional view, taken along the plane indicated by line 3-3of Fig. 2; and

Figs. 4 and 5 are corresponding plan views of the complementary parts ofthe apparatus.

rl`he insulation mounting comprises a generally cylindrical cup orcontainer member 10 open only at one end and a disc-like closure member11 adapted to fit within the open end of the container 10. Both of theseparts are made of molded plastic material having a very high arcingpotential, such as polystyrene, which has an arcing potential of theorder of 600,000 volts per inch.

The container 10 supports therein a usual tube socket assembly 12. l

This socket assembly 12 of conventional Voctal form, is supported withinthe container 10 near the bottom wall 13 thereof. The socket is intendedto cooperatewith a high voltage rectifier tube 36. i

Leads 26, 27 and 28. are soldered in place on the appropriate terminallugs 12b of the socket assembly 12 prior to insertion into the container10. Two of the leads 26 and` 27 in this instance are for the filament,and the other lead 28, which is slightly larger, is for carrying theplate current. In the present instance only three leads are required,the plate of the tubebeing connected to a terminal cap 36a.

For mounting the socket, two short integrally molded posts 15 and 16 areprovided that project upwardly from the container base 13. These postsare diametrically' oppositely disposed close to the inner surface of thecylindrical wall 17 of container 10.

Opposite corners of the rhombic insulation base 12a of the socketassembly 12 rest upon the ends of the posts 15 and 16, the socket lugs12b extending toward the base 13 between the posts 15 and 16. The leads26, 27, and 28 extend upwardly about the edges of the socket 12, and outof the open end of the container 10.

Short sheet metal cap screws 22 and 23 pass through the usual aperturesprovided in the corners of the tube socket base 12a and threadedlyengage respectively within recesses 24 and 25 extending longitudinallyof the posts from their upper surfaces. These screws cut their ownthreads within recesses 24, 25.

The disc closure 11 is placed within the container, entirely coveringthe socket 12, exceptfor a circular central area including the recesses12C for receiving the tube pins. This circular area is defined by acentral aperture 35 of the closure 11. This closure 11 has shallowrecesses 30 and 31 suitably located for receiving the heads of the sheetmetal screws 22 and 23, so that the closure 11 can rest firmly upon thetube socket insulation base 12a.

The periphery of the closure 11 corresponds in size and configuration tothat of the interior surface of the cylindrical wall 17 of thecontainer. Recesses or slots 32 and 33, extending inwardly from theperipheral edge of the closure 11, provide clearance for passage of thetwo filament leads 26 and 27. The recesses 32 and 33 are locatedsymmetrically on opposite sides of the recess for one of the cap screws22 or 23. On appropriate insertion of the closure 11, the recesses 32and 33 are generally radially aligned with filament socket pins. Alarger but similar recess 34 is provided for passage of the cathode lead28. The leads 26, 27 and 28 fit closely in the recesses 32, 33 and 34.

The tube 36 may be inserted into the socket 12. The peripheral portionof the cylindrical base of the tube 36 engages about the edges of theaperture 35.

The socket 12 is essentially completely enclosed when the tube 36 is inplace.-

The container 10 conveniently may be held in place by the aid of sheetmetal cap screws 18 and 19, similar tozserewsf22, 23', passing throughapertures in the chassis 14 ,andengaging respectvelydownwardlyopenngrecesses 20 and 21. These recesses 20 and 21 extend upwardly andlongitudinally of the posts 15 and 16, but terminate substantially.vbeneath the# recesses.. 24: and` 25 for.` the screws securing thesocketz 12.5,'1`he sheet metal. screws 18,19; 22rjand 23=aresurtoundedby substantial thicknesses of the polystyrenematerial toensure .appropriate insulation.

Other. mounting means could-.be provided for the container-10. Thus, forinstance, a ange or lugs extending laterally outwardly near thecenter-ofthe container could support .the .container in arecessfformedin therchassis 14./

The complete enclosure forthe` tube socket' 12 completely ensuresagainst creepage Vof .arcs from the terminal lugslzb, Arcing cannotoccur by electrical penetration of the polystyrene material, thethickness of the plastic material being. suticient to` prevent this forpotentials of-.the .order of.20,000 ori40,000 volts.

Theinventor claimsz.

1. In a protective socket structure: a cup member madeentirely ofinsulation material and open only at the top; a socket supported withinthe cup member beneath the-top and in spaced relationship to the bottomof the cup'member; said socket having a plurality of connectorelements;there being clearance between at least aportion of the socket and theinner wall of the cup `member for passageof leads from beneath thesocketupwardly of the cup member; and a closure member slidablyaccommodated .in the cup member, and having a central openingregistrable with said connector elements for insertionofprongs of anelectronic tube; one of said members providing openings for upwardpassage in the cup of leadsfrom beneath-the socket; atube when insertedinto said socket providing with the members an enclosure for the spacebeneath the socket.

2. The combination as set forth in claim 1 in which the cup member hasdiametrically disposed integrally formed posts of insulation materialextending interiorly of the cup member from the bottom thereof, the topof the posts providing surfaces uponwhich opposite sides of the socketmay rest; the posts havngrecesses at said surfaces for cooperation withfastening means for the socket, said posts also having recesses at theirlower ends opening exteriorly at the bottom. of the cup` for cooperationwith fastening means for securing the cupimember to a chassis or th'elike; the said top and bottr'an recesses of each postbeing,substantially..y aligned, and the inner ends thereof being spacedfrom each other.

References Cited in the tile of this patent- UNITED STATES PATENTSl1,964,541 Soreny June 26, 1934 2,206,736 Sutter l.'fuly 2,1940 2,450,873Antony Oct. 12, 1948 2,493,756 Fetherolf Ian. 10, 1950 2,556,956 Bentonlune 12, 1951 2,563,775 Del Camp .Aug. 7, 1951 2,658,183 KlostermannNov. 3, 1953 2,701,869 Hobson Feb. tl, 1955' FOREIGN PATENTS 537,868Great Britain Julyv 10, 1941

